First thing you will need to do is create a Point Group that includes all of the cogo points. Then you have a few options. You could export the Point Group to a CSV file and then create the Toposurface from that. Or you can create a Surface (in C3D) from the Point Group, then link in the dwg and create a Topo from the TINN layers.

I typically go the Surface route, since importing points from a CSV (that was created in a survey file) will often cause problems in Revit.

Care to elaborate? I'm very much a fan of (AutoCAD dataextraction) of XYZpoints-to-.csv-to-topo and have had no "issues" to date.

If the points are from a survey file, then they will most likely be very far away from the origin. If you try to create a Toposurface from points like this, you will frequently get the warning "Imported Toposurface Points are located a large distance from the model and might not display properly. Points will be centered on the model instead." The imported points are then pretty much rubbish, since Revit will import them however and wherever it deems convenient.

That has been my experience at least. I'm sure it is possible to modify the points so that they are not too far away from the origin. But I frequently need the dwg import for more than just generating a Toposurface, so that workflow makes the most sense.

In their entirety, but relative to one another the points are still good - so if/when this happens we will relocate the generated topo to the survey location, using the points (in both) for the move tool.

But I understand the frustration with the limitation - it's a great tool, and could be greater*.


*and no Autodesk folk, that does not give you your cue to chip in "well there's InfraWorks"... because, well, we'd have already bought C3D if it was THAT big an issue.

Thanks for the tips guys.

Can either of you describe the steps for extracting points from AutoCAD? I have very little (read none) ACAD experience.

Edit: I exploded the aecc points in ACAD. I could then import the info into revit wich generates a topo with 4 points per point (at the end points of each cross) which isn't cricket. I can't seem to get data extract to give me x,y,z points, and I only get 1 point created if I generate a topo from the .csv I extracted...

Yeah, standard ACAD points will create 1 point per endpoint of the cross marking the point (thus the 4 points). To create a better Topo, you should use contour lines or a TINN. You can generate both contours and TINN in C3D by creating a Surface from your points, but if the CSV method is working then that is probably easier.

Thanks for the response!

I don't have C3D, or this process would be much easier (I assume) and I would have the skills...

The .csv method isn't working for me. As I stated above the .csv file only contains 1 point as far as revit is concerned, and a manual edit of the ,csv show all the points bout no x,y,z points.

What I would like is a dwg file with the tin points so I can create a toposurface from the imported instance in Revit.

Steps to achieve this would be most helpful :-)

(off the top of my head)

Open the survey drawing in Autocad
Identify the point or block element that's been used by the originator, (they should have an Position X, Position Y & Position Z value) - note the units (m or mm) also
Command Line: Dataextract
Wizard Steps...
First Page : Define the name and location of the .dxe (dataextraction definition file) - I treat this as sacrificial
Next Page : Select the drawing(s) you wish to extract from (selecting model space only)
Next Page : Select the element you identified earlier in the objects found by the wizard
Next Page : Select the properties of that element you wish to extract (Position X, Position Y & Position Z)
Next Page : Remove Name and count columns, combine identical rows.
Next Page : Select "Export" and set location and name of file - and save to .csv

(at this point I tend to swing the .csv into excel to check for monstrous anomolies, but this comes through in Revit, so isn't strictly necessary)

In Revit, create toposurface (From points) and select the aforementioned .csv



Done-diddly-done.

Cheers Snowy, very descriptive!

Unfortunately :banghead:

In the original file:

• data extract works, but no x,y,z fields present.
• Points don't have x,y,z in properties palette.
• Dataextract exports all the properties (thus missing x,y,z).

After Exploding points:

• Each point is a block a unique name.
• Each Block has X,Y,Z coordinates.
• Unfortunately When I get to page 3 (Data Extraction - Select Objects) there is nothing in the list.

Grrrrargh! Time to call a friend! (hopefully one with teamviewer)